1. Field of the Invention
The present invention relates to inertial bullet pullers which are devices utilized to remove the bullet from the case of cartridge type round of ammunition. Inertial bullet pullers operate by first imparting a rapid motion to the cartridge and then bringing the case thereof to a quick stop. When the case slows down it tries to slow down the bullet too, thereby imposing tension on the connection between the bullet and case. If the tension force is great enough the connection parts, which is the desired result. The tension force is proportional to the time rate of change in the momentum of the bullet and for any given bullet mass is proportional to the time rate of change in bullet velocity. The latter depends on the initial velocity of the bullet and upon the length of time required to stop it, which in turn depends on the speed of propagation of the elastic shock wave through the material carrying the cartridge case.
2. Discussion of the Prior Art
Prior art inertial bullet pullers include a rigid cartridge carrier in the form of a transparent, plastics material tube having an opening at one end adapted to receive a cartridge and provided at its other end with a head portion adapted to be struck against a hard surface. A cartridge support is provided at the one end of the carrier tube for engaging the cannelure or other portion of the cartridge case. The head end of the carrier tube extends beyond the nose of the bullet and is closed with its interior being tapered at the lower end.
In use, a cartridge is placed in the carrier tube and supported therein by the cartridge support which engages the cannelure. A securing cap is provided for holding the cartridge support to the end of the carrier. The head portion at the end of the carrier tube is repeatedly struck against a hard surface such as the top of a table until the bullet pulls free of the case. To facilitate accelerating the carrier to a high velocity and striking it against a fixed hard surface the carrier is provided with a handle extending transversely from the carrier tube. The resulting carrier and handle combination has the overall shape of a hammer.
Prior art bullet pullers employ catridge supports in the form of an open-sided washer which extends from the top of the cartridge carrier to underneath the upper side of the cannelure when the puller is in use. A snug-fitting polyethylene cap is slipped over the upper end of the carrier and frictionally engages the carrier tube and holds the washer and cartridge in place. Such a cartridge support is the source of some difficulty because a plurality of support washers having differing inner diameters must be employed in order to accommodate cartridges having different diameter cannelures. Also, after each use it is necessary to pull the tight-fitting cap off the end of the carrier.
Another form of cartridge support employed by prior art bullet pullers consists of a U-shaped plate which has a variable width between its tines in order to adapt it to cannelures of different diameters. However, such a cartridge support has so little area of engagement with the cannelure that it readily shears if the carrier is struck too hard.
An improvement over the above inertial bullet pullers is disclosed in my U.S. Pat. No. 3,646,661, the disclosure of which is herein incorporated by reference. According to my prior inertial bullet puller, an annular segmented support is provided at the upper end of the carrier of the bullet puller which is extendable into and retractable from the cannelure of a cartridge placed therein. Additionally, the annular segmented support is configured to fit a wide range of cartridges having cannelures of different diameters. The annular segmented support comprises a plurality of arcuate shape members or segments adapted to be annularly disposed at the upper end of a carrier. A garter spring extends around the segments providing a resilient force for urging the segments radially inwardly to an extent limited either by engagement with a cartridge or by the otherwise spaced apart sides of the segments coming into engagement. A cam surface is provided for positively urging the segments radially inwardly and holding them positioned beneath the upper wall of a cartridge cannelure. The cam surface is carried by a cap that threadably engages the upper end of the carrier tube adjacent the cannelure.
Although the inertial bullet puller disclosed in my U.S. Pat. No. 3,646,661 improved over the existing prior art, it fails to operate as easily and efficiently as desired. Under ideal conditions, the head portion of the carrier tube must strike a hard surface squarely so that the carrier tube and, thus, the cartridge from which the bullet is to be removed are perpendicular to the striking surface. That is, the force vector developed by striking the hard surface with the head portion of the carrier tube should be parallel to the axis of the cartridge from which the bullet is being extracted. If the carrier tube is not perpendicular to the surface being struck, the force vector cannot be parallel with the axis of the cartridge being disassembled which results in the bullet being extremely difficult to extract.
The inertial bullet puller in my U.S. Pat. No. 3,646,661 rarely works ideally and more often than not requires numerous raps against a hard surface--often as much as eight or more--to disengage the bullet from the case. That inertial bullet puller fails to operate easily and efficiently to remove bullets from their case because it was designed with a handle which is completely perpendicular to the carrier tube. The completely perpendicular configuration of the handle with respect to the carrier tube makes it difficult for a person using the inertial bullet puller to position his/her wrist in a manner which allows the head portion of the carrier tube to be easily struck squarely against a hard surface. Thus, because squarely striking the head portion is extremely difficult, my prior inertial bullet puller requires numerous blows to disengage the bullet from its case.
Furthermore, uncentered blows along the carrier tube head portion weakens the material used to make the carrier tube, thereby causing premature material failure. That is, when the head portion is not struck squarely, the force vector is not applied to the cartridge but rather is absorbed by the inertial bullet puller itself causing the carrier tube material to crystalize and prematurely break.
Another design deficiency not related to the handle position is that once the bullet disengages from the case, it is necessary to remove the securing cap before it may be retrieved from the carrier tube. Although the cartridge support was originally intended to part sufficiently far enough to allow the bullet to pass, it was discovered that no matter how much the carrier tube was shook or the securing cap rapped against a hard surface, the bullet would not pass and could not be removed without first removing the securing cap.
The inertial bullet puller disclosed in my U.S. Pat. No. 3,646,661, therefore, is subject to premature breakage, is rather tedious to use, and requires a notable time investment when a significant number of bullets are pulled. Such performance characteristics are less than desirable to the ordinary shooting enthusiast.
Accordingly, the present invention improves over the prior art and especially my U.S. Pat. No. 3,646,661 by solving the above problems.